MRI detection of multi focal breast carcinoma: Report from the International Breast MRI Consortium

504 Background: Prior single institution studies suggest MRI may improve the assessment of the extent of cancer within the breast, and thus reduce the risk of leaving macroscopic disease in the breast following breast conservation. We report on the rate of MRI and mammography detection of multi-focal breast cancer in a prospective, multi center trial. Methods: 1004 women with suspicious mammographic and/or clinical findings were enrolled into IBMC 6883 at 17 institutions in the US, Canada and Germany. Women underwent mammography and MRI prior to biopsy of the suspicious index lesion. In addition to characterizing the index lesion, additional incidental lesions (IL) detected by mammography and MRI were noted and characterized. An IL was defined as a finding separated from the index lesion by at least 2 cm. All index lesions and suspicious ILs were recommended for biopsy. Results: 428 of 1004 (43%) women had an index lesion diagnosis of cancer. Of these 428 women, MRI detected at least 1 suspicious IL in 10...